Biopsy forceps are used to obtain tissue samples from a particular site in a patient's body for analysis. Such samples can be taken from the heart, stomach, lungs and the like. Typical biopsy forceps include a long flexible catheter tube having a pair of opposed jaws at a distal end and a handle with an actuator at the proximal end. The physician can manipulate the actuator to open and close the jaws.
In order to take a tissue sample from a patient, the physician must insert the catheter tube into a guide sheath which has been inserted into one of the patient's vessels. Next, the distal end of the biopsy forceps is inserted into the guide sheath, which then guides it into the patient's vessel. From the patient's vessel the physician can direct the catheter tube to the site the physician wishes to biopsy. Once the catheter tube is directed to the biopsy site, the physician can control the jaws using the handle, which remains outside the patient's body. By using a trigger located on the handle, the physician can open and close the jaws of the device in order to take a tissue sample. Once the tissue sample has been taken, the physician must keep the jaws in a closed position to remove the sample from the patient's body. Once the sample has been removed from the patient's body, it can be removed from the forceps and examined.
Multiple handle assemblies have been used to maneuver the catheter tube and jaw assembly into the proper position to perform the biopsy. The first biopsy forceps did not contain a locking mechanism to keep the jaws opened while the physician removes the biopsy sample. Therefore, the physician had to hold the jaws open while positioning the jaw assembly for tissue removal, which often required the use of two hands or another person.
Other biopsy forceps contain a locking mechanism to lock the forceps in a closed position. By locking the forceps in a closed position the physician is able to ensure that the jaws do not cut the patient's vessel as the catheter tube travels to the biopsy site and also ensures that the tissue sample remains in the jaws once the sample is taken.
Later biopsy forceps locking mechanisms are used to lock the forceps in an open position. By locking the biopsy forceps in an open position, the physician is able to position the jaws for tissue sample removal without having to hold the biopsy forceps in the open position. In addition, these biopsy forceps remain in a closed position while unlocked to enable the physician to more easily move the catheter tube through the patient's vessel and to remove the tissue sample from the patient's body. These biopsy forceps also allow the physician to remove the tissue sample from the jaws without the aid of another person to hold the jaws in the open position. However, these locking mechanisms are incorporated into the handle body, which can result in the forceps lock slipping and the jaws closing before the physician wants them to.
Accordingly, what is needed is a locking mechanism, which is not incorporated with the handle body. By having the locking mechanism incorporated with the handle body the potential for the physician to accidentally release the lock while positioning the jaws at the biopsy site increases. Also what is needed is a locking mechanism which is easier for the physician to control.